Nuts have frequently to be removed from male threaded parts such as studs or bolts on which they have been placed, for example to allow equipment to be dismantled, and this is often difficult because the effects of corrosion make it impossible to turn the nut under the force that can be applied manually by a spanner. Nuts that cannot be released by ordinary means can be chiselled off by brute force or burnt off by oxy-acetylene torches but neither of these methods is to be recommended because of safety factors and the risk of damage. Instead, the nuts can be removed in a more controlled manner by use of a proprietary nut splitter tool or device.
The operation of such known splitter devices is described below with reference to FIGS. 1-3, prior art, of the accompanying drawings.
The device shown in FIG. 1 comprises a frame 1 with an interior in which can be received a screwthreaded nut 2 received on a stud or a bolt 4 provided with a mating external screw thread. A cutter blade 5 is guided by the frame for movement towards and away from the nut 2 as indicated by the arrow 6. To split the nut 2, the blade 5 is moved into cutting engagement with it, hydraulically or mechanically, in a linear manner, reacting against the frame 1.
It is a disadvantage of the device of FIG. 1 that it merely splits the nut 2 apart by a small amount, as shown at 7 in FIG. 2, and causes damage to the bolt 4. The nut 1 remains in situ on the bolt 4 and is distorted by the cutting operation so as to be no longer of a shape to suit regular spanners. The split nut 2 can be rotated through 180.degree. and cut again, but the technique is less than satisfactory especially when work is being done under difficult conditions, for example in undersea locations.
This disadvantage can be overcome by use of the prior art nut splitter device of FIG. 3 which resembles that of FIG. 1 except that the frame 10 mounts a blade 11 opposing the movable cutter blade 5, so that the nut 2 is split into two equal portions. It is however a disadvantage of this device that substantial clearance is required on the far side of the nut 2 from the movable blade 5, in order to accommodate not only the frame 1 but also the fixed blade 11. Frequently, such clearance is not available.
The invention accordingly has as its object the provision of a fastener splitter device in which the above-mentioned disadvantages are avoided.